The White Sox claimed right-hander Zach Stewart off waivers from Pittsburgh, the team announced Thursday. Stewart pitched for the White Sox in 2011 and 2012 before heading to Boston as part of the deal that landed the Sox Kevin Youkilis last June.

Stewart, 26, pitched in 28 games with the White Sox, making nine starts. In his career, Stewart has a 7.51 ERA over 14 starts in which he's allowed 18 home runs. He's fared better as a reliever, but still owns a 5.02 ERA out of the bullpen with seven home runs allowed in 28 23 innings.

The right-hander was acquired by the White Sox in 2011 along with Jason Frasor in a deal with Toronto which sent Edwin Jackson and Mark Teahen to the Blue Jays. He came close to throwing a perfect game on Sept. 5, 2011 in Minnesota, holding the Twins without a baserunner until allowing a leadoff double to Danny Valencia to open the eighth inning. Stewart wound up throwing a one-hit shutout in that start.

The White Sox added Stewart to their 40-man roster, which now has 39 players on it.